Electrical condenser



Jan. 16, 1940.

s. s. CRAMER I ELECTRICAL CONDENSER 3 Sheets-Sheet 1 Filed Dec. 11, 1931 fl. fiwy ATTORNEY INVENTOR Jan. '16, 1940- s, 5, CRAMER 2,187,017

ELECTRICAL CONDENSER Filed Dec. 11. 1957 s Sheets-Sheet 2 ,j' Ma g! 74 Z? N 9;,

2? i T I 7 INVENTOR 10g 23 2 5 frame,

ATTORN EY mutual-111.10, 1940 -Stanley B. Gramer, Haddon s a in m N. 1., Il-

Heights, ents, to Condenser assignm Development Corporation, Newark, N. 1., a corporation of New Jersey Application December 11, m1, Serial No. 119.221

13 Claims. 01. 175-415) This invention relates to improvements in variable electrical condensers such as are used in radio receiving sets. In my Patent No. 2,101,985 issued December 14, 1937, I have pointed out the necessity for making small condenser units and still maintain the necessary capacity for use in connection with the tunable circuits, and at the same time reduce the cost of construction. This patent also shows and describes a certain type of construction of condenser frame which makes it possible to reduce the space between the condenser plate units to reduce the size and yet maintain the desired capacity.

I have also shown and described certain ways and means for mounting the stator units to the frame bars.

My present invention has for one of its objects I the further cheapening of the cost of construction of the condenser frame and also to get a cheaper method of mounting the stator units and trimmer plates when used, to the condenser frame.

From the experience gained in making several .million unit condensers arranged in gangs or as single units, I have found through the use of a rigid frame such as described in my patent heretofore referred to, that when the "very rigid metallic r shown and described in said patent are properly constructed and assembled to the end and shield plates, that there is no need for any auxiliary bars between the end plates, in which case the stator units must be mounted to the rigid frame rods.

In my patent to which reference has been made, I have shown how this may be done by slotting frame rods longitudinally of their length and staking the insulators in position in these slots. This construction takes an extra operation on the rods and th re y increases the expense. My present application is directed to a cheaper and better way-of mounting the stators directly to these rigid frame rods. v

My invention will be readily understood by reference to the annexed drawinlfl wherein Figure 1 is a plan view of a three-gang condenser showing my' new construction applied thereto, the plates of the stator and rotor being merely indicated in position by dotted lines and the view showing one method of mounting a trim- Figurei is aview'ofldgure 3 looking from left to risht.

Figure5is aview ofFigure3 looking fromright to left.

Figure 6 is a view of a frame rod of the threesupports of Figures 3 to. 5 inclusive fastened thereto.

gang condenser shown in Figure 1 with the stator Figure '1 is a view on an enlarged scale showing one method of fastening the insulator carrying the terminal to the frame rod.

Figure 8 is a view similar to Figure 7 but show-' ing a modified form of the fastening means.

Figure 9 is a view similar to Figures '1 and 8 but u showing a still further modified form of the fastening means.

Figure 10 is a view looking down at the top of Figure 7 but with the insulator end and portions of the rod shown in section.

. Figure 11 is a view similar to Figure 10 of the construction shown in Figure 8.

Figure 12 is a view similar to Figure 10 but of the construction shown in Figure 9.

Figure 13 is a plan view of a two-gang condenser showing a different method of applying a trimmer plate.

Figure 14 is a side elevation of one of the units of the gang condenser of Figure 13.

Figure 15 shows merely, in a two-gang condenser with a modified form of. supporting the stator units from the frame bars.

- Figure 16 is a side elevation of Figure 15.

Figure 1'1 is a side elevation of a two-gang condenser showing a further modified form of construction.

Figure 18 is a bottom view of Figure 1'7, showing a modified form of construction.

Figure 19 is a partial sectional view on the line lU-IQ of Figure 18,- the trimmer plate being removed.

Figure 20 is a fragmentary view looking at the outlines frame for so bottom of Figure 17,- but showing a modified construction.

' Figure 21 is a fragmentary view on the line 2i--2l of Figure 20.

Figure 22 is a sectional view taken onFigure 2 through one of the frame members and one of the insulators supporting a stator and its trimmer plate.

'Figure 23 isa plan viewoftheblank usedin making the metal mounting strip for fastening the stator insulators of Figures 15 and 16 to the frame member.

ligureziisasidev iew ofthemembershown frame members I and 2 are fastened together by relatively heavy metallic rods I and 8 in the manner as indicated in my Patent No. 2,101,985. Brace and shield plates 7 and 8 are carried by these rods I and I in the manner indicated.

- '15 When the rods I and 8 are being operated on to provide the grooves for receiving the end plates I .and 2, they are simultaneously operated on by a suitable tool or tools to'cut a plurality of grooves or'recesses 8 spaced by the uncut portions l8.

Describing now one stator unit, an insulator I I is provided having a plurality of slots l2 formed therein which are adapted to receive the uncut portions or flanges it. After the insulator H has been placed in position, the shaft is staked in a any satisfactory manner, three of which are indicated in Figures 7 to 12 inclusive. In Figures 7 and 10 the staking I8 is what may be termed a line stake. In other words, the shaping tool makes a cut l3 about as indicated in Figures 7 and 10 thereby spreading the metal of the flanges l8 sufliciently to securely grip the side walls of the slots l2 to hold the insulator ll securely to the frame rod, it being understood that all of the staking operations for each insulator are preformed at once and as a matter of fact the necessary number of insulators may be simultaneously staked-to the rod.

Before the insulator II is assembled and staked to its respective rod, the stator terminal plate 4 II is attached thereto and as shown in Figures 3 to 5 inclusive, the sides of the insulator II are slotted to receive inwardly extending flngers II and II for soldering the stator tie bars thereto. The terminal plate 14 is also provided with clips I I1 and i8 which are bent over the edge and in contact with the back side of the insulator II as shown in Figures 3 and 4. The terminal plate II is also provided with a lug II for making electrical contact to the terminal plate. The plate ll is also provided with a clearance hole 28 to receive an adjusting screw which is adapted to enter a screw threaded hole 2i in the insulator l l', these holes being provided to receive a trimmer plate adjusting screw 22. The plate ll may,'however. II be threaded to take the screw 22.

As shown in Figures 1 and 2, a trimmer plate- 28 is positioned in the grooves 8 on the opposite sideof therods I and 8 from the insulator l I, and staked in position by the flanges II in a manner do similar to that described with respect to the insulator" ll. While I preferto stake the trimmer plate 28 in position, it may be left unstaked as the adjusting screw 22 will hold it in operative position, As shown in Figure 2, the trimmer plate c5 28 extends downwardly over the terminal plate II but is insulated therefromby a suitable insulator such as a piece of mica 24 and insulated from the screw 22 by an insulator 2!. In' the form of assembly shownin Figures 8 and .11, the staking is done by a toolwhich flattens the'flange II in a manner somewhat as indicated at 28, while in Figures land 12 the staking is done by flattening as in Figure 8 and at the same time spreading the flattened portion by a longitudinal spread- 76" ing of the metal as at 21, r

. top of the insulator II.

By mounting the trimmer plate directly to the frame rod, the trimmer plate is held at ground potential as described in R. E. Cramer application Serial No. 51,591 filed November 26, 1935, so

that by this arrangement the shield and brace 5 plates 1 and 8 need not extend beyond the width of the frame for the reason stated in said application.

In Figures 13 and 14 I have shown'how the trimmer plate 28 may be mounted on the same 1 side of the frame rods I and I as the insulator and staked in position when the insulator is attached to these rods.

In Figures 15 and 16 the stator terminal plate 28 is of the type and is fastened to the insulator ii in a manner similar to that shown in my patent to which reference has been made, but the insulator is fastened to the frame bars I and I in a somewhat different manner than shown in Figure 6 in that a suitable bracket is fastened to the upper part of the insulator ii. The metallic bracket is provided with arms 29 and 88 which are staked in suitably formed grooves in the rodsI and I, the stak'ing operations being indicated at II, the arms 28 and 38 preferably a being formed with recesses 22 when they aremade. The bracket has side lugs 88 and 84 which are bent over the edge and back of the insulator I i and a central lug SI bent downwardly over the The terminal plate 28 I} has 'rearwardly projecting lugs 88 which extend in close proximity to thestator tie bars for solder ing thereto which is described in Cramer Patent No. 2,087,902, issued July 22, 1937.

In Figure 17 I have shown a very, small compact two-gang unit and in this. arrangement the frame rods, only one of which, I, is shown, are located near the bottom of the end plates l and 2, I but as has been stated, due to the rigidity of this construction, I have found, for a small unit a of this type, that the bar is still rigid enough to maintain. the spacing of the condenser plates. in this construction the insulators II are staked plate is attached to the insulator in the same manner as in Cramer Patent No. 2,087,902. The

trimmer plate is shown mounted on one of these units, it being staked on the outside of the insulator II and extending upwardly over the so terminal plate 88, but'insulated therefrom in the manner heretofore described,

In Figures 18 and 19, I have indicated how the condensers, for example that shown in Figure 17, may be mounted in some other manner than from is one of the end plates. .In this construction a pair of plates 88 and I8, one for each of the condenser units, may have portions cut out to form flngers II which may be staked in the grooves 8 intherodsIa-ndiinamannersimilartothefl method of attaching the insulators II to said rods. The plates 88 and II are provided with bosses 42 formed by forcing out the metal suiii-' ciently so that the bosses may be threaded to receive mounting screws. [One plate may be used as for the two plates 88 and 48, provided the brace and shield plate I does not extend below the plane of the rods I and 8. V

In Figures 20 and 21, spade clips ll, having flngers 44 adapted to be positioned in the grooves 10 practice may v tion with the material forming said slots.

' including end plates bracket fastened that the details for carrying my invention into be varied considerably without departing from the spirit of the same and the scope of the appended claims; for example, in the construction shown in Figures 15 and 16, the metallic arms 29 and 30 may be soldered or otherwise securely fastened to the outer periphery of the rods I and 8, and the insulating strip llmaycarry a different form of terminal means for attachment to the stator tiebars.

What I claim is:

1. In an electrical condenser having a frame fastened together in nonwarping relationship by metallic rods disposed one on each side of the frame; means for supporting a stator group of plates, anchored together by tiebars, from said rods, said means comprising longitudinally spaced, arcuately arranged formations in the outer periphery of said rods, insulating strips carrying terminal plates having parts adapted to be fastened to said stator tiebars, and means for anchoring said insulators directly and securely to saidformations.

2. Electrical condenser stator mounting means asset forth in claim 1, further defined in that said last-mentioned means includes a metallic to its cooperative insulating strip, the bracket having arms extending into operative position with said formations on the rods and fastened in said position.

3. In an electrical condenser having a frame including end plates fastened together in nonwarping relationship by metallic rods disposed one on each side of the frame; means for supporting a stator group of plates, anchored together by tiebars, from said rods, said means comprising longitudinally spaced, arcuately arranged formations on the outer periphery of said rods, insulating strips carrying terminal plates at one end thereof, the plates having parts extending toward the stator tiebars for attachment thereto, the opposite end of said insulating strips having spaced slots therein to cooperate with said rod formations, portions of which enter said slots and adapted to be staked into gripping rela- 4. Electrical stator mounting means as set forth in claim 3, further defined inthat a trimmer plate may be held in position on at least one of said rods by formations to fit the rod formations, a part of the trimmer extending over the terminal plate but insulated therefrom, with means for adjusting the trimmer plate with respect to said terminalplate.

5. Electrical stator mounting means as set forth in claim 3, further defined in that a. trimmer plate may be held in position on at least one of said rods by formations to fit a part of the trimmer extending over the terminal plate but insulated therefrom, with means for adjusting the trimmer plate with respect to said terminal plate, and further defined in that the trimmer plate engages the rod formations on the opposite sides of the rod from that engaged by the insulating strip.

6. Electrical stator mounting means as set forth in claim 3, further defined in that a trimmer plate may be held in position on at least one of said rods by formations to fit the rod formations, a part of the trimmer extending over the terminal plate but insulated therefrom, with means for adjusting the trimmer plate with respect to 'said terminal plate; and further defined in that the trimmer plate is fastened in position by the fastens the insulatsame staking operation that as set forth in claim 7, that the insulating on their surfaces next to the stator,

the rod formations,'

ingstriptotherodthestaklnginsm'in thatthe trimmer plate is in contact with the frame or at ground poten 7. Inan electrical condenser having a frame including end plates fastened together in nonwarping relationship by metallic rods disposed one on each side of the frame; means for supporting a stator group of plates, anchored together by tiebars, from said rods, said means comprising annular spaced grooves in said rods, carrying terminal at one end thereof, the plates having parts adapted to be attached to the said rod flanges, the flange portions lying in said slots and being staked so as to grip the insulating strip at the walls of the grooves.

8. Electrical condenser stator mounting means as set forth in claim 'i, further characterized in that the insulating strips are fastened to the rods on their surfaces next to the stator, while trimmer plates are positioned on the rods on their outer portions and extend into cooperative relationship with said terminal plates, therefrom, with means for adjusting the position thereof.

9. Electrical condenser stator mounting means further characterized in strips are fastened to the rods while trimmer plates are positioned on the rods on their outer portions and extend into cooperative relationship with said terminal plates, but insulated therefrom, with means for adjusting the position thereof, that the trimmer plate has its end which engages the rod slotted so as to removably fit the flanges on the rod, so when the adjusting means for the trimmer is removed the trimmer plate can be detached.

10. Electrical condenser stator mounting means as set forth in claim I, further characterized in that a trimmer plate is staked to a rod when the insulating strip is staked thereto, plate extending in cooperative pos'tion with the terminal plate, but insulated therefrom, with means for adjusting its position with thereto.

11. In an electrical including end plates warping relationship by one on each side of the frame; means for supporting a stator group of plates, anchored'together by tiebars, from said rods, said means including an insulating strip having means at one end for fastening the strip to said tiebars, and having means at the opposite end adapted to be fastened to exterior peripheral portions of said rods by displaced portions thereof.

12. In an electrical condenser having a frame including end plates fastened together in nonwarping relationship by metallic rods one on each side of the frame; means for supporting a stator group of plates, anchored together by tiebars, from said rods, said means comprising longitudinally spaced, arcuately arranged formations on the outer periphery of said rods, insulating strips carryin terminal plates having parts adapted to be fastened to said stator tiebars, means for anchoring said insulators into said formations, and means for mounting the condenser frame comprising a metal plate extending transversely across the bottom of the frame and having portions anchored in said arcucondenser having a frame fastened together in nonmetallic rods disposed but insulated and further characterized in respect ately arranged formations on said rods, the plate having means therein to receive mounting holding devices.

13. In an electrical condenser having a frame 1 including end plates fastened together in nonwarping relationship by metallic rods disposed one on each side of the. frame; means for, supporting a stator group of plates, anchored together by tiebars, from said rods, said means io 'comprising longitudinally spaced, arcuately ararmor? ranged formations on the outer periphery of said rods, insulating strips carrying terminal plates having parts adapted to be fastened to said stator tiebars, means for anchoring said insulators into said formations, and means for mounting the condenser frame comprising metal parts an-- chored in said arcuateiy arranged formations and extending so as to engage a mounting support.

s'rANmYs. (71mm. 

